/*
 * Copyright 2024 LinQingYing. and contributors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * The use of this source code is governed by the Apache License 2.0,
 * which allows users to freely use, modify, and distribute the code,
 * provided they adhere to the terms of the license.
 *
 * The software is provided "as-is", and the authors are not responsible for
 * any damages or issues arising from its use.
 *
 */

package com.linqingying.cangjie.diagnostics

import com.intellij.openapi.util.NotNullLazyValue
import com.intellij.psi.PsiElement
import com.intellij.util.containers.Interner
import com.intellij.util.containers.MultiMap

class DiagnosticsElementsCache(val diagnostics: Diagnostics, val filter: (Diagnostic) -> Boolean) {

    companion object {

        private fun buildElementToDiagnosticCache(
            diagnostics: Diagnostics,
            filter: (Diagnostic) -> Boolean
        ): MultiMap<PsiElement, Diagnostic> {
            val elementToDiagnostic: MultiMap<PsiElement, Diagnostic> =
                createConcurrentMultiMap()
            for (diagnostic in diagnostics) {
                if (filter.invoke(diagnostic)) {
                    elementToDiagnostic.putValue(diagnostic.psiElement, diagnostic)
                }
            }

            return elementToDiagnostic
        }
    }

    private val elementToDiagnostic: NotNullLazyValue<MultiMap<PsiElement, Diagnostic>> = NotNullLazyValue.atomicLazy {
        buildElementToDiagnosticCache(
            this.diagnostics,
            this.filter
        )
    }


    fun getDiagnostics(psiElement: PsiElement): MutableCollection<Diagnostic> {
        return elementToDiagnostic.value.get(psiElement)
    }


}

fun createStringInterner(): Interner<String> =
    Interner.createStringInterner()

fun <K, V> createConcurrentMultiMap(): MultiMap<K, V> =
    MultiMap.createConcurrent<K, V>()
